Epoxy Resin, Epoxy Resin Composition Containing the Epoxy Resin as an Essential Component and a Cured Product Containing the Epoxy Resin as an Essential Component

ABSTRACT

A new epoxy resin represented by following general formula comprising, possessing one or more than one primary hydroxyl group and one or more than one epoxy group in one molecular, and said epoxy resin is useful for photo curing method. 
     
       
         
         
             
             
         
       
         
         wherein 
         E: epoxy resin residue 
         c: 1, 2, 3 
         d: 1, 2,3 
         c+d=4

FIELD OF THE INVENTION

The present invention relates to an epoxy resin which is useful forphoto curing, an epoxy resin composition and an epoxy resin curedproduct, in particular, a new epoxy resin, an epoxy resin compound andan epoxy resin cured product of the present invention are useful for apaint, an adherent, a photo art, a sealing agent, a molding agent and amaterial for electric or electronic photo circuit.

DESCRIPTION OF THE PRIOR ART

In general, an epoxy resin is widely used for electronic parts, electricmachine and tools, car parts, FRP or sport supplies because of excellentadhesive property, heat resistance and molding ability. A cured productof epoxy resin can be obtained by heating an epoxy resin using a curingagent. As a curing agent to be used, amine curing agents or acidanhydride agents can be mentioned. However, term for usable of an epoxyresin composition that uses these curing agents is limited becausecuring reaction progresses gradually at room temperature and viscositybecomes thicker.

By a photo curing method which cures epoxy resin using a photopolymerization initiator, an epoxy resin composition having excellentlybetter preservation stability than using said amine agents or photopolymerization initiator can be obtained, because curing reaction doesnot cause as long as photo energy is not irradiated.

A photo curing method of an epoxy resin is characterized to blend aphoto polymerization initiator, and a composition which providespliability and improves reacting ability by blending polyols is general(not patent document 1). Since reacting speed of epoxy group of epoxyresin with primary hydroxyl group of polyols is faster than reactionspeed of epoxy groups each other, reacting ability is improved (notpatent document 2). However, if the molecular weight of the blendedpolyols is low, problem of volatilization at curing process or problemof unsaturated curing by moisture absorption are pointed out. Further,when the molecular weight of the blended polyols is high, problem ofdeterioration of heat resistance caused by decrease of crosslinkingdensity is caused.

Not patent document 1: The Dow Chemical company “CYRACURE CycloaliphaticEpoxides Cationic UV Cure”

Not patent document 2: “Hikari Oyo Gijyutsu•Zairyo Jiten”

OBJECT OF THE INVENTION

The inventors of the present invention investigated a new epoxy resinthat is useful to a photo curing method, and have found out that a newepoxy resin possesses one or more than one primary hydroxyl group andone or more than one epoxy group in one molecular represented byspecific general formula can provide a epoxy resin composition or epoxyresin cured product not only whose reacting ability is improved andpliability is provided, but also problems of volatilization, highermoisture absorption and lower heat resistance, which are pointed out inconventional polyols blended epoxy resin composition or epoxy resincured product, are dissolved, and accomplished present invention. Andthe object of the present invention is to provide an epoxy resin, anepoxy resin composition and epoxy resin cured product which can dissolvethe problems that conventional epoxy resin, epoxy resin composition andepoxy resin cured product have, that is, problems of volatilization,moisture absorption and heat resistance caused by blending polyols.

Above mentioned object is accomplished by using a new epoxy resinrepresented by general formula 1 comprising, possessing one or more thanone primary hydroxyl group and one or more than one epoxy group in onemolecular.

a: 0, 1, 2, 3, . . .b: 0, 1, 2, 3, . . .c: 0, 1, 2, 3, . . .d: 1, 2, 3, . . .

wherein a+c: 1, 2, 3, . . .

l: 1, 2, 3, . . .m: 0, 1(EP) is a reaction residue of epoxy resin and is specificallyrepresented by general formulae 2 and 3.(E) is a reaction residue of epoxy resin and is specifically representedby general formulae 4 and 5.(X) is a carbon alone or hydrocarbon group and can contain nitrogenatom, phosphorus atom, oxygen atom or sulfur atom.(A) is a hydrocarbon group of acid anhydride residue and can containnitrogen atom, phosphorus atom, oxygen atom or sulfur atom.R is a hydrogen or hydrocarbon group and can contain nitrogen atom,phosphorus atom, oxygen atom or sulfur atom.

n: 1, 2, 3, . . .Y is a hydrocarbon group and can contain nitrogen atom, phosphorus atom,oxygen atom or sulfur atom, further can be a structure of linear,branch, ring, aromatic ring or heterocyclic.

q: 1, 2, 3, . . .r: 1,2Q is a hydrocarbon group and can contain nitrogen atom, phosphorus atom,oxygen atom or sulfur atom, further can be a structure of linear,branch, ring, aromatic ring or heterocyclic.Z indicates —O—, —COO—, —N═

u: 0, 1, 2, 3, . . .t: 1, 2, 3, . . .Y′ is a hydrocarbon group and can contain nitrogen atom, phosphorusatom, oxygen atom or sulfur atom, further can be a structure of linear,branch, ring, aromatic ring or heterocyclic.

w: 1, 2x: 0, 1, 2, 3, . . .y: 1, 2, 3, . . .Q′ is a hydrocarbon group and can contain nitrogen atom, phosphorusatom, oxygen atom or sulfur atom, further can be a structure of linear,branch, ring, aromatic ring or heterocyclic.Z′ indicates —O—, —COO—, —N═.

BRIEF ILLUSTRATION OF DRAWINGS

FIG. 1 shows molecular weight distribution by GPC of epoxy resinobtained in Example 1.

FIG. 2 shows measuring results of FTIR of epoxy resin obtained inExample 1.

FIG. 3 shows molecular weight distribution by GPC of epoxy resinobtained in Example 5.

FIG. 4 shows measuring results of FTIR of epoxy resin obtained inExample 5.

FIG. 5 shows molecular weight distribution by GPC of epoxy resinobtained in Example 6.

FIG. 6 shows measuring results of FTIR of epoxy resin obtained inExample 6.

DETAILED DESCRIPTION OF THE INVENTION

Details of the present invention will be illustrated as follows.

New epoxy resin in the present invention is represented by generalformula 1, which possesses one or more than one primary hydroxyl groupand one or more than one epoxy group in one molecular.

As one method to prepare the new epoxy resin of present invention, amethod to react all carboxyl groups of the compound which has one ormore than one primary hydroxyl group and one or more than one epoxygroup in one molecular with an epoxy group.

As a specific example of the compound which has one or more than oneprimary hydroxyl group and one or more than one epoxy group in onemolecular, glycolic acid, dimethylolpropionic acid or dimethylolbutanoicacid can be mentioned. Further, said compound can be obtained byreacting alcohols possessing 2 or more than 2 primary hydroxyl groups inone molecular with carboxylic acids containing acid anhydride, however,is not limited to these compounds and can be used by mixing 2 or more ofthese compounds.

As a epoxy resin which reacts with the compound which has one or morethan one primary hydroxyl group and one or more than one epoxy group inone molecular, public known epoxy resin can be used, and specifically,BPA epoxy resins of Tohto Kasei Co., Ltd, such as EPOTOHTO YD-128,EPOTOHTO YD-8125, EPOTOHTO YD-127, EPOTOHTO YD-825GS, EPOTOHTO YD-134,EPOTOHTO YD-011, EPOTOHTO YD-012, EPOTOHTO YD-013, EPOTOHTO YD-901,EPOTOHTO YD-902 or EPOTOHTO YD-903, BPF epoxy resins such as EPOTOHTOYDF-170, EPOTOHTO YDF-8170, EPOTOHTO YDF-870GS, EPOTOHTO YDF-2001 orEPOTOHTO YDF-2004, novolac epoxy resins such as EPOTOHTO YDPN-638,EPOTOHTO YDCN-701, EPOTOHTO YDCN-702 or EPOTOHTO YDCN-703, aralkylnovolac epoxy resins such as ESN-175, ESN-375 or ESN 485, amine epoxyresins such as EPOTOHTO YH-434 or YH-434L, glycydil ester epoxy resinssuch as EPOTOHTO YD-171 or YD-172, aliphatic epoxy resins such asEPOTOHTO YH-300, EPOTOHTO ZX-1542, EPOTOHTO PG-207 or EPOTOHTO PG-207GS,alicyclic epoxy resin such as EPOTOHTO ST-3000 or EPOTOHTO ZX-1658,EPOTOHTO ZX-1658GS, EPOTOHTO ZX-1715, HBPA-DGE, DCPD-EP or TCPD-EP whichare products of Maruzen Petrochemical Co., Ltd., YX8000 or YX8034 whichare products of Japan Epoxy resin Co., Ltd., CELLOXIDE 2021, CELLOXIDE2021A, CELLOXIDE 2021P or CELLOXIDE 3000 of Daicel Chemical Industries,Ltd or hydrogenated dimer acid epoxy resin can be mentioned, however, isnot limited to these compounds and can be used together with.

Reaction is carried out by blending more than 1.1 mol, desirably, morethan 2.0 mol, more desirably more than 3.0 mol of epoxy group to 1.0 molof carboxyl group.

Reaction between the compound which has one or more than one primaryhydroxyl group and one or more than one epoxy group in one molecular andepoxy resin can be carried out by public known method for synthesis.That is, the reaction can be carried out by blending the compound whichhas one or more than one primary hydroxyl group and one or more than oneepoxy group in one molecular and epoxy resin and heating. Inactivesolvent or catalyst can be used, if necessary. Reaction temperature isfrom 50° C. to 200° C., desirably from 80° C. to 180° C. End point ofthe reaction can be decided by confirming vanish of carboxyl group by aninstrumental analysis or by confirming degree of acid by chemicalanalysis. Reaction time is from 1 hour to 6 hours.

As a usable inactive solvent, solvent that does not have hydroxyl groupis desirable, and specifically, benzene, toluene or xylene can bementioned, however, is not intending to be limited to these solvents andcan be used together with.

As a usable catalyst, imidazoles such as 2-methylimidazol or2-ethyl-4-methylimidazol, phosphines such as triphenyl phosphine,tritolyl phosphine, tris(2,6-dimethoxyphenyl)phosphine or phosphoniumsalts such as tetrabutylphosphoniumbromide, tetrabutylphosphoniumiodide,ethyltriphenylphosphoniumbromide or ethyltriphenylphosphoniumiodide canbe mentioned, however, is not intending to be limited to these solventsand can be used together with.

The compound which has one or more than one primary hydroxyl group andone or more than one epoxy group in one molecular can be also obtainedby reacting alcohols having two or more than two primary hydroxyl groupin one molecular with carboxylic acids containing acid anhydride.

At the reaction, the compound which has one or more than one primaryhydroxyl group and one or more than one epoxy group in one molecular canbe obtained by carrying out the reaction so as the acid anhydrideequivalent to 1 equivalent of primary hydroxyl group to be smaller than1 equivalent. If the reaction is carried out by 1 equivalent of acidanhydride to 1 equivalent of primary hydroxyl group, the epoxy resin ofthis invention can not be obtained because the primary hydroxyl groupdoes not remain. Further, if the equivalent of acid anhydride to 1equivalent of primary hydroxyl group is larger than 1 equivalent, thereis possibility of gelation at the reaction with epoxy resins becauseacid anhydride remains. Desirable equivalent of acid anhydride issmaller than 1 and more than 0.5 equivalent. By adjusting equivalent ofprimary hydroxyl group and equivalent of acid anhydride, primaryhydroxyl group can be adjusted voluntarily.

As an alcohol having two or more than two primary hydroxyl group in onemolecular, divalent alcohols such as ethylene glycol, diethylene glycol,propylene glycol, dipropylene glycol, 1,4-butanediol, neopentylglycol,1,6-hexane diol, 1, 8-octane diol, cyclohexanedimethanol or spiroglycol,trivalent alcohols such as glycerin, trimethylolethane,trimethylolpropane or hexanetriol, polyvalent alcohols such as sorbitol,sucrose, pentaerythritol, ditrimethylolethane, ditrimethylolpropane ordipentaerythritol, alkyleneoxide adduct of these alcohols can bementioned, however, is not intending to be limited to these compounds,and these compounds can be used together with.

As an acid anhydride, itaconic acid anhydride, citraconic acidanhydride, 2-carboxy-ethyl-methyl-phosphinic acid anhydride, phthalicacid anhydride, hexahidrophthalic acid anhydride, tetrahydrophthalicacid anhydride, methylhexahydrophthalic acid anhydride, methyltetrahydrophthalic acid anhydride, methylnadic acid anhydride, dodecylsuccinicacid anhydride, pyromellitic acid anhydride, benzophenonetetracarboxylicacid anhydride, ethylene glycolbis (anhytrotrimellit), methylcyclohexenetetracarboxilic acid anhydride, trimellitic acid anhydride, naphthalicacid anhydride or acid anhydride disclosed in JP H6-80765 publicationcan be mentioned, however, is not intending to be limited to thesecompounds, and these compounds can be used together with.

Reaction of alcohols with carboxylic acid containing acid anhydride canbe progressed by blending prescribed amount and heating. At thereaction, inactivated solvent or catalyst can be used, if necessary.Reaction temperature is from 50° C. to 180° C., desirably from 80° C. to150° C. End point of the reaction can be decided by confirming vanish ofacid anhydride by an instrumental analysis or by confirming degree ofacid by chemical analysis. Reaction time is from 1 hour to 6 hours.

As an inactivated solvent which is usable at the reaction, it isnecessary that the reacted product can be dissolved, and specifically,benzene, toluene, xylene or methylisobutylketone can be mentioned.However, is not intending to be limited to these compounds, and thesecompounds can be used together with.

By reacting a compound processing two or more carboxyl group in onemolecular with epoxy resins possessing one or more than one primaryhydroxyl group and two or more than two epoxy group in one molecular, anew epoxy resin which has one or more than one primary hydroxyl groupand one or more than one epoxy group in one molecular can be synthesizedtoo.

As a compound possessing two or more than two carboxyl group in onemolecular, oxalic acid, malonic acid, fumaric acid, sussinic acid,glutaric acid, adipic acid, phthalic acid, maleic acid, sebacic acid,itaconic acid, citraconic acid, cyclohexanetricarboxylic acid ornaphthalene dicarboxylic acid can be mentioned. Further, the compoundwhich has more than two carboxyl group in one molecular can be alsosynthesized by reacting afore mentioned alcohols possessing two or morethan two primary hydroxyl group in one molecular with carboxylic acidscontaining acid anhydride. At the reaction, primary hydroxyl group canbe remained.

An epoxy resin possessing one or more than one primary hydroxyl group inone molecular can be obtained by adjusting amount of alkali, amount ofcatalyst, reaction temperature or reaction time so as to add epoxy groupremaining primary hydroxyl group at the epoxylization of a compoundpossessing two or more than two primary hydroxyl group.

A compound possessing two or more than two carboxyl group in onemolecular and an epoxy resin possessing one or more than one primaryhydroxyl group and two or more than two epoxy group in one molecular canbe reacted by public known method. That is, blending prescribed amountof these two compounds and by heating. At the reaction, inactivatedsolvent or catalyst can be used, if necessary. Reaction temperature isfrom 50° C. to 200° C., desirably from 80° C. to 180° C. End point ofthe reaction can be decided by confirming vanish of carboxyl group by aninstrumental analysis or by confirming degree of acid by chemicalanalysis. Reaction time is from 1 hour to 6 hours.

Epoxy resin composition of the present invention is adjusted so asequivalent of epoxy group to 1 equivalent of primary hydroxyl group tobe within 5 to 50 range by blending new epoxy resin of present inventionand/or other epoxy resin. By this adjustment, high reacting ability andexcellent heat resistance of cured product are accomplished.

If equivalent of epoxy resin to equivalent of primary hydroxyl group issmaller than 5 or more than 50, heat resistance is deteriorated.

As a curing agent usable for an epoxy resin composition of the presentinvention, a photo polymerization initiator can be mentioned. As aspecific example of a photo polymerization initiator, onium salts suchas Lewis acid, Br ønsted acid, sulfonium salt, iodonium salt ordiazonium salt can be mentioned. Among these compounds sulfonium salt isdesirable, and among sulfonium salts, aromatic sulfonium salt is moredesirable. Specifically, SANAIDO SI-60L, SANAIDO SI-80L or SANAIDOSI-100L (products of Sanshin Chemical Industry Co., Ltd.), ADEKAOPTOMER-SP-150 or ADEKA OPTOMER-SP-170 (products of Adeka IndustriesCo., Ltd.), CI-5102 (product of Nippon Soda Co., Ltd.), CYRACUREUV1-6976 or CYRACURE UV1-6992 (products of The Dow Chemical Co., Ltd.)can be mentioned. However, is not intending to be limited to thesecompounds, and these compounds can be used together with.

Although blending amount of said photo polymerization initiator differsaccording to light irradiation condition, kind of epoxy resin and amountthereof, kind of photo polymerization initiator or thickness and shapeof cured product, from 0.01 weight parts to 10 weight parts to 100weight parts of epoxy resin.

The epoxy resin composition of the present invention can blendsensitizer, anti aging agent, stabilizer, plasticizer, wax, levelingagent, filler, pigment, dye, flame retardant, foaming agent, antistaticagent, anti mildew agent, viscosity controlling agent or solvents can beblended besides photo polymerization initiator. Further, epoxy resinbesides the new epoxy resin of the present invention can be blended inthe range not to spoil the effect of the present invention.

The epoxy resin cured product of the present invention can be obtainedby photo irradiation and/or heating of the epoxy resin composition ofthe present invention.

As a light to be irradiated at the curing process of the epoxy resincomposition of the present invention, any kind of light which can cureby said photo polymerization initiator can be used according to the kindof photo polymerization initiator.

In a case when UV light is used as above mentioned light, light sourceis not restricted, and for example, ordinary UV light irradiation sourcesuch as fluorescent lamp or high pressure mercury lamp can be used.Further, as a light source, low pressure mercury lamp, xenon lamp, metalhalide lamp, sterilization lamp, lazar light or LE light can be used.

Although illuminance, irradiation amount and irradiation time of saidlight differs according to kind and amount of the photo polymerizationinitiator, and epoxy resin backbone of the present invention, adductsand thickness, can be voluntarily adjusted according to physicalproperty of cured product.

As carried out ordinary in photo curing method, heat curing can becarried out before and after photo irradiation, and curing can be moreprogressed.

By use of epoxy resin composition obtained by the photo polymerizationmethod in which new epoxy resin of the present invention is contained asan essential gradient, epoxy resin composition and epoxy resin curedproduct that dissolves problems of volatilization, high moistureabsorption or lower heat resistance which was the problem ofconventional epoxy resin composition and epoxy resin cured product canbe obtained.

EXAMPLES

The present invention will be illustrated more in detail according toExamples, however, not intending to limit the scope of claims of thepresent invention to Examples.

Example 1

34.0 parts of pentaerythritol (number-averaged number of functionalgroup in one molecular; 4, product of Mithubishi Gas Chemicals Company,INC.), 134.3 parts of RIKACID MH-700 (methylhexahydrophthalic acidanhydride, product of New Japan Chemical Co., Ltd.) and 30.0 parts oftoluene are poured into a separable flask with a condenser, and heatedwith stirring in nitrogen gas atmosphere. Acid anhydride group toprimary hydroxyl group is 0.799. Reaction is carried out at 130° C., andconfirmed that acid anhydride is vanished, then 617.4 parts of HBPA-DGE(hydrogenated BPA epoxy resin, product of Maruzen Petrochemical Co.,Ltd.,) is added, heated and homogenized. As a catalyst, 0.1 parts ofTPP-BB (n-butyltriphenyl -phosphoniumbromide, product of Hokko ChemicalIndustry Co., Ltd.) is dissolved in acetone and added. Reaction iscarried out at 150° C., and reaction is stopped by confirming that acidnumber becomes zero. Epoxy equivalent of the obtained epoxy resin is420.8 g/eq and equivalent of primary hydroxyl group is 3261 g/eq. Molarratio of epoxy group and primary hydroxyl group is 9.31. Molecularweight distribution by GPC is shown in FIG. 1 and measuring result ofFTIR is shown in FIG. 2.

Example 2

Same processes to Example 1 are carried out except changing parts ofRIKACID MH-700 to 151.0 parts and parts of HBPA-DGE to 753.1 parts. Acidanhydride group to primary hydroxyl group is 0.899. Epoxy equivalent ofthe obtained epoxy resin is 381.9 g/eq and equivalent of primaryhydroxyl group is 2160 g/eq. Molar ratio of epoxy group and primaryhydroxyl group is 24.28.

Example 3

Same processes to Example 1 are carried out except changing parts ofRIKACID MH-700 to 159.6 parts and parts of HBPA-DGE to 667.0 parts. Acidanhydride group to primary hydroxyl group is 0.950. Epoxy equivalent ofthe obtained epoxy resin is 408.9 g/eq and equivalent of primaryhydroxyl group is 17212 g/eq. Molar ratio of epoxy group and primaryhydroxyl group is 42.09.

Example 4

Same processes to Example 1 are carried out except changing parts ofRIKACID MH-700 to 100.7 parts and changing epoxy resin to 280.0 parts ofHBPA-DGE and 280.0 parts of CELLOXIDE 2021. Acid anhydride group toprimary hydroxyl group is 0.599. Epoxy equivalent of the obtained epoxyresin is 273.5 g/eq and equivalent of primary hydroxyl group is 1734g/eq. Molar ratio of epoxy group and primary hydroxyl group is 6.34.

Example 5

Same processes to Example 1 are carried out except changing acidanhydride to 167.5 parts of RIKACID HNA-100 (methylnadic acid anhydride)and changing epoxy resin to 491.5 parts of CELLOXIDE 2021 and 216.1parts of ZX-1658 (epoxidized product of cyclohexanedimethanol, primaryhydroxyl group equivalent is 1105 g/eq, product of Tohto Kasei Co.,Ltd). Acid anhydride group to primary hydroxyl group is 0.901. Epoxyequivalent of the obtained epoxy resin is 491.5 g/eq and equivalent ofprimary hydroxyl group is 1734 g/eq. Molar ratio of epoxy group andprimary hydroxyl group is 13.11. Molecular weight distribution by GPC isshown in FIG. 3 and measuring result of FTIR is shown in FIG. 4.

Example 6

Same processes to Example 1 are carried out except changing acidanhydride to 184.0 parts of RIKACID HNA-100 and changing epoxy resin to435.7 parts of CELLOXIDE 2021 and 230.9 parts of ZX-1658. Acid anhydridegroup to primary hydroxyl group is 1.000. Epoxy equivalent of theobtained epoxy resin is 252.6 g/eq and equivalent of primary hydroxylgroup is 4233 g/eq. Molar ratio of epoxy group and primary hydroxylgroup is 16.76. Molecular weight distribution by GPC is shown in FIG. 5and measuring result of FTIR is shown in FIG. 6.

Comparative Example 1

Same processes to Example 1 are carried out except changing acidanhydride to 100.7 parts of RIKACID MH-700 and changing epoxy resin to459.0 parts of HBPA-DGE. Epoxy equivalent of the obtained epoxy resin is450.7 g/eq and equivalent of primary hydroxyl group is 1482 g/eq. Molarratio of epoxy group and primary hydroxyl group is 3.29.

Comparative Example 2

Same processes to Example 1 are carried out except changing acidanhydride to 115.4 parts of RIKACID MH-700 and changing epoxy resin to528.8 parts of HBPA-DGE. Epoxy equivalent of the obtained epoxy resin is435.1 g/eq and equivalent of primary hydroxyl group is 2166 g/eq. Molarratio of epoxy group and primary hydroxyl group is 4.98.

Comparative Example 3

Same processes to Example 1 are carried out except changing acidanhydride to 168.0 parts of RIKACID MH-700 and changing epoxy resin to699.8 parts of HBPA-DGE. Epoxy equivalent of the obtained epoxy resin is418.2 g/eq and equivalent of primary hydroxyl group is not existing.

100 parts of obtained epoxy resins are respectively dissolved incyclohexanon and 0.5 parts of CYRACURE UVI-6976 (Product of The Dowchemical Company) is blended as a photo polymerization initiator. Saidliquid is coated on a releasing film using a bar coater and solvent isremoved at 150° C. for 30 minutes, and light is irradiated by 10 mWilluminance and 8 J/cm² integrated light amount at 365 nm wave lengthusing Unicure system UVX-01212S1CS01(product of USHIO INC.), lamp typeUVL-1500M2-N1, further cured at 150° C. for 60 minutes, then curedproduct is obtained.

Cured product is removed from the releasing film and glass transitionpoint is measured by EXSTAR6200DSC (product of SII Nano TechnologyInc.). Measuring condition is follows. Temperature is programmed fromroom temperature to 200° C. by 10° C./min temperature-programming speed,and first changing point at 2^(nd) cycle is measured as glass transitionpoint. Results are summarized in Table 1.

Infra red absorption spectrum is measured by 1760×(product of PerkinElmer Japan Co., Ltd.). Molecular distribution is measured by liquidchromatography HLC-8120 (product of Tosoh Corporation.).

TABLE 1 Comp. Comp. Comp. Example 1 Example 2 Example 3 Example 4Example 5 Example 6 Exp. 1 Exp. 2 Exp. 1 pentaerythritol 34.0 34.0 34.034.0 34.0 34.0 34.0 34.0 34.0 methylhexahydrophthalic acid 134.3 151.0159.6 100.7 100.7 115.4 168.0 anhydride methylnadic acid anhydride 165.7184.0 toluene 30.0 34.2 15.0 35.2 38.5 23.8 26.4 35.6 acid anhydridegroup to primary 0.799 0.899 0.950 0.599 0.901 1.000 0.599 0.687 1.000hydroxyl group HBPA-DGE 617.4 753.1 667.0 280.0 459.0 528.8 699.8CELLOXIDE 2021 280.0 491.5 435.7 ZX-1658 216.1 230.9 epoxy equivalent420.8 381.9 408.9 273.5 234.5 252.6 450.7 435.1 418.2 primary hydroxylgroup 3917 9271 17212 1734 3075 4233 1482 2166 — equivalent epoxy groupto primary 9.31 24.28 42.09 6.34 13.11 16.76 3.29 4.98 — hydroxyl groupDSC Tg (° C.) 94.1 94.7 92.8 131.1 160.6 156.6 87.8 90.5 90.6

As clearly understood from comparison of Examples 1-3 with ComparativeExamples 1-3, heat resistance of the new epoxy resin which possessesboth primary hydroxyl group and epoxy group is improved in photo curingmethod. Further, it is clearly understood that equivalent ratio of epoxygroup and primary hydroxyl group is desirably 5 to 50. As shown inExample 6, when new epoxy resin having a primary hydroxyl group and anepoxy group is synthesized by using epoxy resin having a primaryhydroxyl group, heat resistance is improved too.

INDUSTRIAL APPLICABILITY

Since the new epoxy resin of the present invention needs not to blendpolyols, problems of compatibility such as separation or white turbiditycaused in blending process can be dissolved. In an epoxy resincomposition of the present invention, problem caused by migration ofpolyol to the surface and adsorb humid in air, that is problem of highmoisture absorption is also dissolved. Further, since monomer is notexisting, problem of volatilization does not cause. Since primaryhydroxyl group and epoxy group are existing in one molecular,crosslinking density of cured product becomes high and heat resistancebecomes better than that of epoxy resin to which polyol is blended.

1. A new epoxy resin represented by general formula 1 comprising,possessing one or more than one primary hydroxyl group and one or morethan one epoxy group in one molecular,

wherein a; 0, 1, 2, 3, . . . b; 0, 1, 2, 3, . . . c; 0, 1, 2, 3, . . .d; 1, 2, 3, . . . wherein a+c; 1, 2, 3, . . . l; 1, 2, 3, . . . m; 0, 1,. . . (EP) is a reaction residue of epoxy resin and is specificallyrepresented by general formulae 2 and 3, (E) is a reaction residue ofepoxy resin and is specifically represented by general formulae 4 and 5,(X) is a carbon alone or hydrocarbon group and can contain nitrogenatom, phosphorus atom, oxygen atom or sulfur atom, (A) is a hydrocarbongroup of acid anhydride residue and can contain nitrogen atom,phosphorus atom, oxygen atom or sulfur atom, R is a hydrogen orhydrocarbon group and can contain nitrogen atom, phosphorus atom, oxygenatom or sulfur atom,

wherein n; 1, 2, 3, . . . Y is a hydrocarbon group and can containnitrogen atom, phosphorus atom, oxygen atom or sulfur atom, further canbe a structure of linear, branch, ring, aromatic ring or heterocyclic,

wherein q; 1, 2, 3, . . . r; 1,2 . . . Q is a hydrocarbon group and cancontain nitrogen atom, phosphorus atom, oxygen atom or sulfur atom,further can be a structure of linear, branch, ring, aromatic ring orheterocyclic, Z indicates —O—, —COO—or —N═,

wherein u; 0, 1, 2, 3, . . . t; 1, 2, 3, . . . Y′ is a hydrocarbon groupand can contain nitrogen atom, phosphorus atom, oxygen atom or sulfuratom, further can be a structure of linear, branch, ring, aromatic ringor heterocyclic,

wherein w; 1, 2 . . . x; 0, 1, 2, 3, . . . y; 1, 2, 3, . . . Q′ is ahydrocarbon group and can contain nitrogen atom, phosphorus atom, oxygenatom or sulfur atom, further can be a structure of linear, branch, ring,aromatic ring or heterocyclic. Z′ indicates —O—, —COO— or —N═.
 2. Thenew epoxy resin of claim 1 obtained by reacting epoxy resins with acompound possessing one or more than one primary hydroxyl group and oneor more than one carboxyl group in one molecular.
 3. A method forpreparation of the compound of claim 2 obtained by reacting alcoholspossessing one or more than one primary hydroxyl group in one molecularand a carboxylic acid containing acid anhydride and the new epoxy resinof claim 1 obtained by reacting said compound with epoxy resins.
 4. Thenew epoxy resin of claim 1 obtained by reacting epoxy resins possessingone or more than one primary hydroxyl group and one or more than oneepoxy group in one molecular with a compound possessing two or more thantwo carboxyl group.
 5. An epoxy resin composition containing an epoxyresin according to claim 1 as an essential component, wherein equivalentof epoxy group to 1 equivalent of primary hydroxyl group in saidcomposition is 5 to
 50. 6. The epoxy resin composition of claim 5comprising a photo polymerization initiator as a curing agent.
 7. Acured product prepared by heat curing or photo curing of the epoxy resincomposition of claim 5.